This invention relates to devices for projecting balls. More specifically, it relates to a class of devices employed as aids in perfecting the game of tennis. Such devices typically are capable of receiving a large supply of tennis balls and of projecting them along a desired path towards the player who wishes to practice. In this manner the player can strike a number of balls to improve his tennis swing. The ball throwing device has a mechanism for reciprocating the fence and the upper tube with respect to each other.
Prior device have generally been large expensive machines suitable for purchase only by tennis clubs and the like. Additionally, such previous devices were not completely reliable and satisfactory in that balls fed into the machine tended to jam or otherwise improperly feed causing an interruption in the practice session. Similarly, adequate control over the path of the ball projected from these devices could not be obtained particularly where air pressure was utilized to eject the balls.
U.S. Pat. No. 3,272,194 to Egbert discloses a portable ball throwing machine which utilizes a spring biased arm for projecting tennis balls. This device does not have a ball bin but rather utilizes an S-shaped ball tube for storing a number of balls. The tube ends at the bottom of the machine and a complex lift mechanism including an arm, ball cup and retaining arm is employed to bring each ball to the top of the device where it is struck by the throwing arm. No means is provided for oscillating the machine to vary the ball trajectory.
It is accordingly an object of the present invention to provide a ball projecting device which is lightweight and portable.
It is a further object of the present invention to provide a motor operated ball projecting machine.
Another object of the invention is to provide a highly reliable ball projecting machine which includes means for feeding balls from a ball bin to the projecting means with a minimum of ball jams.
A further object of the invention is to provide a ball projecting device which permits convenient and accurate control of the force with which the balls are ejected from the device.
Another object of the invention is to provide means for oscillating the ball throwing machine from side to side by a selectable amount to vary the pattern with which the balls are projected towards the player.
Other objects and advantages of the invention will be apparent from the remaining portion of the specification.